The Z2 system was an evolution of the Z1 model. Major change was a new CPU board using a 4 Mhz. Z80 microprocessor. The system, always based on the S-100 bus, proposed 21 connectors for S-100 cards and a stronger power supply able to supply additional peripherals. The front panel didn't offer any switches or control leds. 8080 based software made with the Z-1 model could run on the Z-2 system

The Z2-D (September 1977) version included 64 KB of RAM, one or two 92 KB (then 184 KB) formatted floppy drives and controller card.
The Z2-H system appeared in July, 1980. Using the Z-2 basis but including a 11 MB hard disk, two dual sided floppy disc drives and 64 KB of RAM memory.

OK, one last post: The Z-2H still required a floppy disk to boot up CP/M and get the whole thing started. Slow! I eventually figured out a way to use Cromemco''s 32KB E-PROM board and their Bank Switching capability to temporarily swap in the E-PROM board, copy a CP/M image from it to RAM. switch the E-PROM board back out and jump to CP/M''s startup address. Wow, startup was now instantaneous! I should have passed that technique back to Cromemco. :(

Wednesday 24th October 2018

Paul Hansknecht (United States)

Oops, in my previous post, the Z-2H was announced in 1980, and we acquired one in early 1981, not 1971.

Wednesday 24th October 2018

Paul Hansknecht (United States)

I was the technical half of a two-man company in the 70s and early 80s. The other guy was the owner, the salesforce, and the money man. Our plan was to build turnkey systems for the "zillions of small companies that could profitably use a micro-computer but didn''t know it". So in the late 70s, we bought a Z-2D kit so I could get started. It had a 4MHz Z-80, 64KB of RAM, 2 DSDD 184KB floppy disk drives, and a Televideo 950(?) terminal! We equipped it with the Cromemco Assembler and their FORTRAN IV Compiler. It was a beast! But oh, those floppy disks! Constantly swapping them in and out... Put in the editor disk (WordStar?) to work on some program. Take it out and put in the Compiler. Take it out and put in the linker. Save the executable to a separate floppy Test it. Repeat till satisfied. We knew most businesses would have a hard time keeping their program and data disks straight, but that was the best we could do. Then in 1971, Cromemco announced the Z-2H! OMG, 10MB! We swooned over the possibilities, and, unbelievably, the money man agreed to buy the add-on kit to convert our Z-2D to a Z-2H! We qualified as a Cromemco OEM at the time, so we got a 20$ or 25$ discount and paid a mere $7,500 (or something like that), and WOW! That completely changed the micro world! I could now "instantly" switch between an unlimited number of programs without touching a floppy disk! And that meant our customers could, too! This truly turned the microcomputer into a viable business solution overnight!